Tomac Unveils Diplomat 29er and Carbon Supermatic 120 Mountain Bikes

The Diplomat takes what they’ve learned with 26″ bikes and applies it to a nimble handling big wheeled bike with 120mm of travel. The Supermatic takes everything they’ve learned and makes it lighter, stiffer and faster…also with 120mm of travel.

Jump past the break to get the scoop…

2011 TOMAC DIPLOMAT 29er MOUNTAIN BIKE

“What we’re trying to do with the bike was to make a 120mm travel bike with the benefits of the 29″ wheel but with the feel of our 26″ wheeled bikes,” says Tomac’s marketing guy, Joel. “So, we really worked on getting a really short chainstay (17.5″) and wheelbase to give it a lively feel and keep it easy to pull the front wheel off the ground when you need to. Also, the top tube has a really low standover height, which makes it pretty maneuverable.”

They also needed to look at stiffness. With the bigger wheels, it’s more of a design challenge because you have a longer wheelbase and longer tubes…and we wanted to make this a longer travel bike, which is likely to be ridden in more aggressive terrain. So we used a tapered headtube that’s short to keep the cockpit low but gussetted for strength, a box section downtube and the design of the rear triangle, which is described below.

The result is an XC bike with full 6069 aluminum frame that passes their own downhill bike tests, which also passes EN standards with flying colors. It has cable mounts for a dropper post, too, in case you actually want to test their tests.

Like the Supermatic below, they eliminated the pivot near the rear axle. To accomplish this, they put a short rocker link at the top of the seatstays where it meets the shock. This rocker link allows for a structurally solid rear, connected rear triangle that doesn’t need a pivot at the rear dropout. The rocker link is mounted to a small bridge that’s bolted to the ends of the chainstay. Combined with taller rocker link that mounts to the shock and front triangle, it creates a laterally rigid frame.

The Diplomat frameset ($1,299) will come with a shock and headset, and two complete bikes will be offered. Package one, the Diplomat 1 comes with a Fox fork, EA70 wheels, XT drivetrain, Easton carbon handlebar and Thomson post and stem, MSRP is $4,099. Claimed weight is 28lbs (Large).

The Diplomat 2 gets SLX, EA50 wheels and parts and retails for $3,299. Frames are available in black (shown) or white. Claimed weight is 29.5lbs (Large).

Frame weight with shock and headset is 7lbs for a Large. Med, Large and XL are available. All sizes have two cage mounts.

2011 TOMAC SUPERMATIC 120mm

The new full carbon Supermatic is the big deal, with Tomac calling it a “trail bike with XC sensibilities and downhill capabilities.” The highlights are:

120mm travel for 120 or 130mm travel fork

5 pound/2270g frame with Fox RP23 shock

Full carbon fiber front and rear triangles

Tapered head tube (1-1/8″ – 1.5″)

69.5º head angle M/L sizes!

13.1″/335 mm BB height!

17″/433 mm chainstay length

Tomac started with a 5lb frame (with shock) goal and worked from there. They also wanted to exceed any prior frame stiffness benchmarks they had set and exceed EN testing for both impact and fatigue resistance. In order to do that, they decided on a compact dual triangle design – the rear triangle is one piece that uses a carbon flex stay to replace a pivot at the rear dropout – with heavily shaped tubes to resist bending. Oversized aluminum pins and pivot shafts, a reinforced tapered headtube and a short machined rocker arm bring it all together.

The geometry is designed to accommodate a 120mm to 130mm suspension fork. To handle that travel the way this bike is meant to be ridden, they gave it a box section top- and downtube with rounded corners. That latter detail, Tomac says, helps to counter torsional loading. There are stiffening layers of carbon on the sides of the tubes and additional layers in the top- and downtubes to better distribute loads.

Up front, the tapered headtube was reinforced for better frontal impact, and the BB area was beefed up to maximize power transfer.

Unlike the Diplomat, the Supermatic uses an open “V” shaped rear triangle with a main pivot at the bottom and rocker link at the top. There’s a bridge between the seatstays just behind the seat tube and they have a box section design to keep them from flexing independently. The design serves the purpose while cutting weight.

More pics, click to enlarge. The seat tube is straight to allow for full insertion of the seatpost.

The Supermatic comes with a 3M microfiber adhesive on the downtube to protect it from impacts and damage.

In order for a bike to handle predictably, use its suspension effectively and transfer power the way we want it to, it needs to be stiff. For Tomac, this meant developing an entirely new carbon pre-preg material and finding a new factory to make the bike.

During manufacturer, EPS inserts eliminate voids and ensure consistent wrapping, and vacuum suction helps pull the resin into the layers of carbon fiber to remove bubbles and wrinkles. The carbon weaves and resins are custom for Tomac, and they use a low-heat curing process with consistent pressure on the entire frame. This is done so the carbon maintains the original structure without heat-induced expansion or cooling contraction. The mold are removed after the frame is cured.

After testing 30 shocks, several eye-to-eye lengths and various damping and spring combos, they had it dialed. It comes with a Fox RP23 with a low compression ratio for light rebound and compression settings and a low Boost Valve setting. The suspension was designed to have a neutral feel, which they say removed the need for an overly damped shock to improve pedaling efficiency.

The Flex Stay, originally developed for their Carbide SL, moves just 2º at the full 120mm travel. For the Supermatic, they designed it to be stiffer. The bike shows only 1mm of chain growth per 10mm of travel, which would translate to 12mm at full compression, or just less than 1/2″.

Comments

According to your graph the chain growth figure of 1/2″ is wrong. It appears to only grow 4.5mm at its maximum point (60mm of travel) before that figure returns to nearly zero at full travel.

Adam - 01/21/11 - 9:15am

The bikes look killer, but in the description of the Diplomat’s suspension design, the statement, “Like the Supermatic below, they eliminated the pivot near the rear axle.” is incorrect. This is true for the Diplomat, which uses a monoshock rear triangle (solid triangle), while the Supermatic uses Tomac’s familiar pivotless flexible seat stay design. It’s Fisher “Cake” vs Fisher “Sugar”.
The description for the Supermatic, however, gets the distinction between the two suspension designs correct.

Dream bike – Carbon Diplomat w/Sram XX. I bet it would come in around 24lbs.

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